Improvement in coal screens and chutes



M. R. ROBERTS.

Goal-Screens and Chutes.

NO. 140,077. H PatentedJune17-.I873,

AM PHOTO'LITHOGHAPHIC cu. m? (osanmvs macsss.)

UNI ED STATES PATENT Orriqfi MARTIN R. ROBERTS, OF SAN FRANCISCO,CALIFORNIA.

IMPROVEMENT IN COAL SCREE NS AND CHUTES.

Specification forming part of Letters Patent No. 140,677, dated June 17,1873; application filed April 26, 1873.

To all whom it may concern:

Be it known that I, MARTIN RICKARD ROBERTS, of San Francisco city andcounty, State of California, have invented a Combined Portable Hopper,Chute, and Screening Apparatus; and I do hereby declare the followingdescription and accompanying drawings are sufficient to enable anyperson skilled in the art or science to which it most nearly appertainsto make and use my-said invention or improvement without furtherinvention or experiment.

My invention relates to a portable apparatus which is intended moreparticularly for receiving, cleaning, and delivering into carts coal andother like substances, which are usually dumped upon the wharf indischarging ships.

The usual method of discharging ships of their cargo of coal is to raisethe coal from the vessel in tubs by a steam hoisting apparatus, and dumpit in a pile upon the wharf, from which it is removed by carts to thedifierent coal-yards, where it is screened so as to separate the finerportion or screenings from the large and marketable or more merchantableportion.

My invention consists of a portable apparatus having a double hopper,chute, and screens, so arranged that by dumping the coal or othersubstances to be handled from the tub into the upper hopper, the fineportions or small particles will be separated in two or more grades fromthe coarser portions, and be deposited in separate piles, while thecoarser pieces are caught in the second hopper, from which they can beconveyed through a chute into the carts which convey them to thecoalyards, thus requiring but one operation to discharge the cargo,screen the coal, and load it into the carts.

In order to more fully illustrate and explain my invention, reference ishad to the accompanying drawings forming a part of this specification,in which- Figure I is a perspective view of my invention. Fig. II is aplan view of the blank to be used when the apparatus is used only as achute.

A A represent a strong frame, which is properly stayed and braced so asto withstand the concussions to which it will be subjected. At one sideof the top of this frame, I secure two boards, B B, at an obtuse angleto each other in the form of a trough, but leave their lower endsseparated so as to providea space, 0, between them for the purposehereinafter described. These boards form what I call the upper hopper.The board B forms an exten sion to one side, D, of a large hopper, O,which is located in the body of the frame below the upper hopper. Thisside D of the large hopper slopes'toward the opposite side of the frame,and is constructed of parallel wires secured at short distances apart,so as to form a screen over which the coal or other substance must passin descending from the upper to the lower hopper, and through which thesmall particles, up to a certain size, will fall, leaving the largerpieces, which cannot pass through the screen, lying in the second orlarge hopper. The lower hopper is contracted toward its lower end, and achute, F, extends from it out over the opposite side of the frame fromthat on which the upper hopper is located. A gate, h, which will be morefully described hereafter, serves to retain the coal in the chute andhopper until it is desired to allow it to pass from the chute into acart or other vehicle. An independent grate or screen, I, of finer meshthan the grate D, is secured in an inclined position in the frame A A,below the screen 1), so as to receive the particles of coal or othersubstance which pass through the upper screen, and which serves to:again separate it into two grades. This screen stands at an angletransversely to the upper screen, so that the particles which pass downit on account of not being small enough to pass through the meshes willbe carried off to one side of the machine, while the finer portions,which pass through the screen, will fall upon the floor or wharfdirectly under the frame.

,wo or more of these screens can be used, and the size of the meshes canbe varied according to the substance to be cleaned, and the number andquality of the grades into which it is desired to separate the substancebeing discharged.

The frame A A will be mounted upon small wheels, so that it can be movedfrom one place to another upon awharf in order to be placed in positionto receive the discharging cargo of different ships; but when moving itfrom one wharf to another, I employ axles across each end of the frame,upon which strong wheels are placed, so that the entire machine can bedrawn along similar to any wheeled vehicle.

The upper trough, which is formed by the boards B B, is as long as themachine, so that in dumping the load, any vibration or swinging of thetub while it is being emptied will not cause the load to be dischargedoutside of the hopper as long as the machine is properly located, andordinary care is exercised in dumping it. This form of the upper hopperalso allows the substance which is dumped into it to spread over alarger surface and thus be more thoroughly screened than when the hopperis smaller. l

When it is not desired to screen the article or substance to beunloaded, a false bottom or metal blank, K, is placed upon the gratingor inclined side D of the larger hopper, so that the substance will becarried directly through the chute into the cart or wagon intended toconvey it away.

The gateor cut-off which I use consists of a lever-bar, 19, which hasone end pivoted-to the frame, so that it will extend transversely acrossabove the end of the chute. Metal teeth It extend downward across themouth of the chute, so as to bar the entrance. When the cart is inposition beneath the chute, the

free end of the lever is raised so as to clear the teeth from the mouthof the chute, and allow the substance to pass through by its gravityinto the cart.

By this arrangement coal can be discharged from ships, screened, andloaded into carts not only at a great saving of expense in handling it,but with less wastage, as the large and more marketable pieces or lumpswill not be broken when dumped in this machine, as they always are to agreater or less extent when dumped from the height of twenty or thirtyfeet upon the wharf or coal pile.

Having thus described my invention, what 1 claim, and desire to secureby Letters Patent is- 1 The receiving-hopper B B, in combination withthe hopper O, with its screen or grating side D, chute F, with itstoothed gate h, and one or more independent screens I, all combined andarranged substantially as and for the purpose above described. 2. Themetal blank or false bottom K, in

combination with the receiving-hopper B B,

hopper O, chute F, and gate h, substantially as and for the purposeabove described.

In witness whereof I hereunto set my hand and seal.

' -M. R. ROBERTS. LL. s.]

Witnesses:

GEO. H. STRONG, HENRY K. MooRE.

